Encapsulation of electronic components on substrate for hearing device

ABSTRACT

Disclosed is a system, a hearing device and a method for encapsulating one or more electronic components on a substrate. The method comprises providing a dam on the substrate, the dam is provided around the one or more electronic components, the dam comprises a dam material comprising an electrically conducting material. The method comprises providing a liquid fill encapsulation material within the dam on the substrate, the fill encapsulation material encapsulates the one or more electronic components, the fill encapsulation material is configured to solidify, the solidified fill encapsulating material comprises a first surface exposed to surroundings. The method comprises applying a cover material on the first surface of the solidified fill encapsulation material, the cover material comprising an electrically conducting material, whereby the one or more electronic components are encapsulated and electromagnetically shielded.

RELATED APPLICATION DATA

This application is a continuation of International Patent ApplicationNo. PCT/EP2020/084796 filed on Dec. 7, 2020, which claims priority to,and the benefit of, European patent application No. 19218072.7 filed onDec. 19, 2019. The entire disclosures of the above applications areexpressly incorporated by reference herein.

FIELD

The present disclosure relates to a system, a hearing device and amethod for encapsulating one or more electronic components on asubstrate by providing a dam on the substrate around the one or moreelectronic components, and by providing a fill encapsulation materialwithin the dam to encapsulate the electronic components.

BACKGROUND

As electronic components on a substrate produces electromagnetic noise,it is an advantage to provide that the electronic components areelectromagnetically shielded, such as by encapsulation. There is a needfor an improved method for encapsulation of electronic components forproviding improved systems and hearing devices with encapsulatedelectronic components.

SUMMARY

Disclosed is a method for encapsulating one or more electroniccomponents on a substrate. The method comprises providing a dam on thesubstrate. The dam is provided around the one or more electroniccomponents. The dam comprises a dam material comprising an electricallyconducting material. The method comprises providing a liquid fillencapsulation material within the dam on the substrate. The fillencapsulation material encapsulates the one or more electroniccomponents. The fill encapsulation material is configured to solidify.The solidified fill encapsulating material comprises a first surfaceexposed to surroundings. The method comprises applying a cover materialon the first surface of the solidified fill encapsulation material. Thecover material comprises an electrically conducting material. Therebythe one or more electronic components are encapsulated andelectromagnetically shielded.

It is an advantage to encapsulate electronic components on a substrate,such as a printed circuit board (PCB) in a hearing device. Encapsulationmay provide an electromagnetic (EM) shield of the electronic components.Such EM shield is an advantage as the electronic components on asubstrate may produce a lot of EM noise. In electronic devices, such ashearing devices, there may be magnetic coils or electromagnetic coilsfor providing wireless communication with other electronic devicesand/or for transmission or reception of radio frequency signals. In ahearing device, there may be a magnetic induction (MI) coil and/or theremay be a tele coil. These coils should be electromagnetically (EM)shielded from the electronic components. The electromagnetic field ofthe electronic components may be an electric field or a magnetic field,when in the near field of the emitting waves. If the electromagneticfield is impending, e.g. from other devices, like mobile phones, hearingaid accessories etc., then it may be electromagnetic since it may thenbe in the far field. In particular, when using rechargeable batteries inan electronic device, the rechargeable battery may have a high voltage,and such high voltage may disturb for example a magnetic induction (MI)coil. High voltage may be converted to a lower voltage by e.g. aconverter. The converter may emit electrical and/or magnetic noise,depending on conversion topology.

It is an advantage to encapsulate electronic components, asencapsulation may also provide mechanical protection of for examplediscrete components, integrated circuit (IC) chips and bonding wires.

It is an advantage to encapsulate electronic components, asencapsulation may also provide that moist around the electroniccomponents can be avoided or reduced.

It is an advantage that the encapsulation protects the electroniccomponents from moisture, dust, dirt and solvents.

It is an advantage of the method that the one or more electroniccomponents are encapsulated and electromagnetically shielded. This isobtained by providing that the dam material comprises an electricallyconducting material and by providing that the cover material comprisesan electrically conducting material. The electrically conductingmaterial of the dam and of the cover may be the same electricallyconducting material. The electrically conducting material may be a metalor a metal alloy such as for example silver (Ag). The electricallyconducting material may be a paste containing one or more metals. Thedam may be placed on top of the ground ring of the substrate or may beconnected to the ground ring. The dam is placed around the electroniccomponents to be encapsulated. The dam may be a closed structure. Thedam material and the cover material are both conductive, and as they arein contact, they connect to each other. Thereby the dam, such as theoutside surface of the dam, and the cover material provide theelectromagnetic shielding of the electronic components. Thus, both thedam and the cover have electromagnetic interference (EMI) properties dueto the electrically conducting material.

Electromagnetic interference (EMI), also called radio-frequencyinterference (RFI) when in the radio frequency spectrum, is adisturbance that affects an electrical circuit by electromagneticinduction, electrostatic coupling, or conduction. The disturbance maydegrade the performance of the circuit or even stop it from functioning.EMI can be used intentionally, as in the present method, for providingelectromagnetic shielding of the electronic components on the substrate.

When the electronic components are encapsulated on the substrate, thesubstrate may be mounted in a system or in an electronic device, wherebythe electronic components can be performing various functions in thesystem or in the electronic device.

The electronic device may be a communication device, such as a smartphone, tablet, pc, wearable device etc.

The electronic device may be a hearing device. The hearing device may bea headset or earbud(s) for audio communication. The hearing device maybe a hearing protector for protection of e.g. impulse sounds. Thehearing device may be a hearing aid for compensating for a hearing lossof the user. The hearing aid may be any hearing aid, such as a hearingaid of the in-the-ear type, such as in-the-canal type, such ascompletely-in-the-canal type of hearing aid, etc., a hearing aid of thebehind-the-ear type, of the receiver-in-the-ear type of hearing aid,etc.

The hearing device may comprise a microphone configured for convertingan acoustic sound signal from a sound source into an audio signal. Theaudio signal is configured to be processed in a processing unit forcompensation of the hearing loss of the user. The processed audio signalis configured to be converted into a processed acoustic signal by areceiver.

The hearing device may comprise one or more antennas for radio frequencycommunication. The one or more antennas may be configured to operate ina first frequency range, such as at a frequency above 800 MHz, such asat a frequency above 1 GHz, such as at a frequency of 2.4 GHz, such asat a frequency between 1.5 GHz and 3 GHz, during use. Thus, the firstantenna may be configured for operation in ISM frequency band. The firstantenna may be any antenna capable of operating at these frequencies,and the first antenna may be a resonant antenna, such as monopoleantenna, such as a dipole antenna, etc. The resonant antenna may have alength of lambda/4 or any multiple thereof, lambda being the wavelengthcorresponding to the emitted electromagnetic field.

The hearing device may comprise one or more wireless communicationsunit(s) or radios. The one or more wireless communications unit(s) areconfigured for wireless data communication, and in this respectinterconnected with the one or more antennas for emission and receptionof an electromagnetic field. Each of the one or more wirelesscommunication unit may comprise a transmitter, a receiver, atransmitter-receiver pair, such as a transceiver, a radio unit, etc. Theone or more wireless communication units may be configured forcommunication using any protocol as known for a person skilled in theart, including Bluetooth, WLAN standards, manufacture specificprotocols, such as tailored proximity antenna protocols, such asproprietary protocols, such as low-power wireless communicationprotocols, RF communication protocols, magnetic induction protocols,etc. The one or more wireless communication units may be configured forcommunication using same communication protocols, or same type ofcommunication protocols, or the one or more wireless communication unitsmay be configured for communication using different communicationprotocols.

The hearing device may be a binaural hearing device. The hearing devicemay be a first hearing device and/or a second hearing device of abinaural hearing device.

The electronic device or the hearing device may a device configured forcommunication with one or more other device, such as configured forcommunication with another hearing device or with an accessory device orwith a peripheral device.

The method provides that the electronic components are encapsulated onthe substrate. The substrate may be a printed circuit board (PCB) or aseparate plate which is attached to the PCB.

The electronic components may be surface mounted components such astransistors, resistors, capacitors, integrated circuits, inductors,diodes etc. The electronic components may be one or more batteries, suchas rechargeable batteries.

The method comprises providing a dam on the substrate. The dam may be abarrier or a wall. The height of the dam may be from 1 micrometer (μm)to 5 millimeter (mm), such as 10 μm, such as 0.5 mm, such as 1 mm. Thewidth of the dam may be from 0.5 micrometer (μm) to 5 millimeter (mm),such as 0.5-1 mm. The dam is provided around the one or more electroniccomponents. The dam comprises a dam material comprising an electricallyconducting material. The dam may be arranged on a ground ring of thesubstrate or on a connection to the ground ring of the substrate. Thedam may comprise a material being a combination or mix of an epoxy basedmaterial and the electrically conducting material, such as silver. Thedam material may comprise a material such as Tatsuta AE1244. A solventmay be added to the material. The dam may be provided on the substrateby a dedicated manufacturing machine applying the dam material on thesubstrate in a specified area and having a specified shape. The dam mayprovide a closed structure around the electronic components. The dam maycomprise an inside surface pointing towards the electronic components.The dam may be shaped as a closed structure. The closed structure may beshaped as a circle, as an oval, as a rectangle etc. The inside walls ofthe dam structure may point towards each other. If the dam structure isshaped as a rectangle, there may be four walls. Two of the walls, suchas a first wall and a third wall, may be arranged opposite each other,and two other walls, such as a second wall and a fourth wall, bearranged opposite each other. The angle between a first wall and asecond wall may be about 90 degrees. The angle between a second wall anda third wall may be about 90 degrees. The angle between a third wall anda fourth wall may be about 90 degrees. The angle between a fourth walland a first wall may be about 90 degrees. The dam may comprise anoutside surface pointing towards the surroundings. The dam may comprisea bottom part pointing towards, touching and/or being incontact/connecting with the substrate. The dam may comprise a topsurface being parallel to the bottom surface. The top surface may pointtoward the surroundings.

The method comprises providing a liquid fill encapsulation materialwithin the dam on the substrate. The liquid fill encapsulation materialmay be provided before or after the dam material has cured. The liquidfill encapsulation material and the dam material may be cured together.The fill encapsulation material encapsulates the one or more electroniccomponents. The liquid fill encapsulation material may be applied withinthe dam by a dedicated manufacturing machine. The liquid fillencapsulation material may have a specific viscosity providing that theliquid fill encapsulation material can flow and fill all surfaces,holes, cavities etc. on the substrate inside the boundaries of the dam.A distance between two neighbouring electronic components, e.g. adistance between the first electronic component and the secondelectronic component, may preferably be such that the fill encapsulationmaterial may penetrate between the electronic components. The viscosityof the fill encapsulation material may be between 3-1000 Pa*s. Theselected viscosity may depend on design and requirements.

The encapsulation material may contact or be substantially in contactwith, e.g. adhering to, electronic component(s), e.g. the firstelectronic component and/or the second electronic component, for examplesuch that a surface (or at least a part) of the fill encapsulationmaterial adheres to the surface of the first electronic component and/orthe second electronic component. It may be advantageous that the fillencapsulation material adheres to the first electronic component and/orthe second electronic component, such that substantially no air istrapped between the fill encapsulation material and the surface of thefirst electronic component and/or the second electronic component. Thismay further avoid that any moisture penetrates and collects between thefill encapsulation material and the electronic component(s), such as thefirst electronic component and/or the second electronic component, whichmay lead to damage or misfunction of the electronic component(s).

The fill encapsulation material may be an epoxy based material. The fillencapsulation material may for example be a material such as NamicsU8443, Chipcoat U8443, UV-coat 6843, G8345, or the like, e.g. similarnames but with a different suffix. The fill encapsulation material isconfigured to solidify. The liquid fill encapsulation material isconfigured to solidify or become solid after being provided or appliedon the substrate. Solid or solidified in this respect may mean that atleast a part of the fill encapsulation material is solid. When the fillencapsulation material is solid, another material may be applied on atleast a part of the fill encapsulation material. The solidified or solidfill encapsulating material comprises a first surface exposed tosurroundings. When the fill encapsulation material is solid, there is afirst surface of the fill encapsulation material where a cover materialcan be applied. If the first surface is not solidified, the covermaterial may diffuse into the fill encapsulation material. Solidifiedmay not mean cured. Curing may be performed in another step. Curing maycomprise UV curing or heat curing. The fill encapsulation material maychange from first being a liquid material, then a solid material, andthen a cured material.

The first surface of the fill encapsulation material is exposed to thesurroundings. The first surface of the fill encapsulation material maybe exposed to air. The first surface of the fill encapsulation materialmay point towards the surroundings. The first surface of the fillencapsulation material may be parallel with the substrate. The firstsurface of the fill encapsulation material may be an uppermost surfaceof the fill encapsulation material. The other surfaces of the solid fillencapsulation material will point towards the substrate and towards theinside walls of the dam.

The method comprises applying a cover material on the first surface ofthe solidified fill encapsulation material. The method may comprise thatthe cover material is applied on the solidified fill encapsulationmaterial. The cover material may be applied by spraying or jetting, suchas with spray, aerosol or jetting. The cover material comprises anelectrically conducting material. The electrically conducting materialmay be silver. The cover material may comprise a material being acombination or mix of an epoxy based material and the electricallyconducting material, such as silver. The cover material may comprise ormay be a material, such as Genes'ink® Smart spray S-CS11101, Genes'ink®Smart'ink S-CS21303, Genes'ink® Smart'ink S-CS01520, Tatsuta® AE1244,Tatsuta® AE5000A5, Tatsuta® AE5000L, Tatsuta® AE5000ST, or Tatsuta®SF-PC5600 or the like.

As both the cover material and the dam material comprises electricallyconducting material, such as silver or copper, the dam and the coverprovide an electromagnetic shield of the encapsulated electroniccomponents due to the conductivity of e.g. the metal.

The cover material and the dam material may be in contact and/or connector adhere to each. As the dam material may be connected to ground ifarranged on the ground ring of the substrate, the cover material mayhave ground connection through the dam material.

The dam material, the fill encapsulation material and the cover materialmay all be epoxy based materials, whereby these materials will adherewell to each other. Thus, the one or more electronic components areencapsulated and electromagnetically shielded.

It is a problem in prior art that when using jetting technology toencapsulate components, it is difficult to control that theencapsulation material stays in intended place on the substrate. Thismight result in encapsulation material covering keep out areas on thesubstrate. In the electronic industry, a dam epoxy material is commonlyused to keep encapsulation material within keepout zones on a substrate.The dam is then filled up with epoxy material.

It is problem in prior art that when jetting/printing on the sides of adam, using jetting technology, this will introduce bad uniformity of thematerial depending on the height of the dam. It is a problem in priorart that applying EMI materials on jettet encapsulation may result inpoor shielding effectiveness for the EMI shield if the sides of the damare not covered, such as sufficiently covered, by the EMI material.

In prior art, jetting techniques, like a tilted nozzle, to improve sidescoverage of the dam will complicate the production process.

It is thus an advantage of the present method that the prior art dammaterial is replaced with a dam material comprising an electricallyconducting material such as a silver epoxy material.

This provides that the dam is now conductive and can be placed, forexample, on top of the ground ring of the substrate, e.g. PCB, and canbe used to keep encapsulation material out of keep out zones on thesubstrate.

The present method comprises providing fill encapsulation materialwithin the boundaries of the dam. After this encapsulation material hasbeen added then a cover material, for example a silver—epoxy EMImaterial, can be applied, such as by either spray or jetting. The coverEMI material connects to the conductive dam quite naturally.

The conductive dam can be fully solid or have a conductive outer layerto save silver material.

The design of the substrate, such as a printed circuit board (PCB), mayhave a ground ring around the components or area that needs EMshielding. The electronic components, such as surface mounted devices(SMD), may first be assembled on the substrate before providing the dam.Then the following process may be performed. First apply the conductivedam on the substrate, such as on top of ground ring. The height of thedam can vary from for example 1 μm to 5 mm, such as ideally 0.1-1 mm.Then the dam material may be cured if needed. Then the fillencapsulation material is applied inside the dam. Then the fillencapsulation material, and possibly also the dam material, may becured. Curing may be performed using UV light which does not requireheat or time. Curing may be performed by other means. Then a covermaterial, which may be an electromagnetic interference (EMI) material,is applied, such as with either spray or jetting, suing e.g. spray,aerosol or jetting. Finally, a final curing of all the material may beperformed.

In some embodiments, the cover material is provided on the first surfaceof the solidified fill encapsulation material. In some embodiments, thecover material is provided only on the first surface of the solidifiedfill encapsulation material.

In some embodiments, the cover material is not provided on an outsidewall of the dam material. In some embodiments, the cover material isapplied/provided to cover an outside wall of the dam material.

It is an advantage that cover material do not have to be provided onvertical sides of the dam. It is an advantage not to provide covermaterial on vertical sides of the dam, as it is difficult to control thecover material on vertical sides when jetting. As the dam itself isconductive, the cover material need not be applied on the outside wallsof the dam.

It is an advantage that the cover material may have ground connectionthrough the dam material, when the dam material and the cover materialare adhered or in contact with each other, and if the dam material hasground connection, e.g. when the dam is provided on or in connectionwith the ground plane of the substrate.

In some embodiments, the cover material is applied by spraying orjetting. The application of cover material by spraying or jetting may beby spray, aerosol or jetting.

Jetting or non-contact dispensing is an additive process where amaterial is deposited by rapidly shooting it at a substrate withoutmaking any physical contact. Like dispensing, it is a drop on demandprocess which produces consistent results and minimum material wastage.It is a versatile process which allows a material to be deposited in anyshape or pattern. Jetting for electronic packaging and precisionmanufacturing allows device designers to make advanced package designsfor smaller products. Jetting technology is based on valves controlledby actuators such as piezoelectric actuators. These actuators controlopening and closing of the valve. A jetting deposition involves thejetting valve hovering over a defined area of substrate and then openingfor a predefined time period which causes a specific quantity ofmaterial to be jetted out through a nozzle. The rapid ejection of thematerials is caused by pneumatic pressure applied to the material to bejetted. A series of droplets or a steady stream of a material can bejetted to fill an area on a substrate. A jetting system consists of ajetting head, jetting controller, a syringe, XYZ axis movement stage anda pneumatic pressure valve. The material to be jetted is placed in asyringe which is connected to the jetting head. The pneumatic pressurevalve is connected to the other end of syringe through an air hose tocontrol the pressure applied to the contents of the syringe. The jettingcontroller controls the opening and closing of the valve and the periodof time the valve is opened. The XYZ movement stage digitally defines anarea of the substrate where the material is required to be deposited. Acomputer is an optional component of a jetting system, it canco-ordinate the movement of the XYZ stage, opening and closing of thejetting valve. In some cases the jetting controller receives the signalto open and close the valve directly from the movement stage; in suchcases a computer is not essential.

In some embodiments, the method comprises applying an environmentalprotection on the cover material and an outside wall of the dam. Theenvironmental protection may be a protective cover or a protectivematerial. The environmental protection may be an epoxy based material,such that it adheres to the cover material and the dam. Theenvironmental protection is configured to protect the encapsulatedelectronic components, the dam and the cover material against theenvironment, when arranged in an electronic device, such as hearingdevice. The environment may include temperature changes, radiation,moist etc. The environmental protection may be a material such as NamicChipcoat U8443 or HumiSeal UV40HV. The material can be used to protectthe outside of the metal adhesive from contamination.

In some embodiments, the cover material, and/or the fill encapsulationmaterial and/or the dam material are configured to connect to eachother. Thus, the cover material may adhere to the first surface of thefill encapsulation material. An electrical connection may establish,occur or form between the dam material and the cover material. Thematerials may connect to each other due to the material properties, suchas if using epoxy based materials, then the materials will adhere toeach other due to the properties of epoxy. The materials may havethermal properties and/or thermoplastic properties which provide thatthe connect. When the materials connect to each other, it is anadvantage that a closed surface working as an EMI shield is provided.

Epoxy refers to any of the basic components or cured end products ofepoxy resins, as well as a colloquial name for the epoxide functionalgroup. Epoxy resins, also known as polyepoxides, are a class of reactiveprepolymers and polymers which contain epoxide groups. Epoxy resins maybe reacted (cross-linked) either with themselves through catalytichomopolymerisation, or with a wide range of co-reactants includingpolyfunctional amines, acids, acid anhydrides, phenols, alcohols andthiols, usually called mercaptans. These co-reactants are often referredto as hardeners or curatives, and the cross-linking reaction is commonlyreferred to as curing. Reaction of polyepoxides with themselves or withpolyfunctional hardeners forms a thermosetting polymer, often withfavorable mechanical properties and high thermal and chemicalresistance.

In some embodiments, the fill encapsulation material comprises an epoxybased material, an acrylic based material and/or a polymer basedmaterial. This material may be a non-conductive material.

In some embodiments, the cover material comprises an epoxy basedmaterial, an acrylic based material and/or a polymer based material.This material may be a non-conductive material. The cover material alsocomprises an electrically conductive material. The non-conductivematerial and the conductive material of the cover may be mixed or may bearranged in separate layers.

In some embodiments, the dam material comprises an epoxy based material,an acrylic based material and/or a polymer based material. This materialmay be a non-conductive material. The dam material also comprises anelectrically conductive material. The non-conductive material and theconductive material of the dam may be mixed or may be arranged inseparate layers.

In some embodiments, the dam material comprises a first material, whichis a mixture of an epoxy based material and the electrically conductingmaterial. Thus, the dam may comprise only the first material. Thus, thedam may comprise for example silver in the entire dam material. Thesolvent of the dam material, e.g. an epoxy based material, may bebetween 10 and 50% depending on material type. The density of thematerial after curing may be between 3 to 5 g/cm3. The weight of theelectrically conducting material, e.g. pure silver, may be 10.50 g/cm3.The ratio of the electrically conducting material relative to thesolvent material may be in the range from 10-60%

In some embodiments, the dam material comprises two materials, wherein aprimary material of the two materials comprises an epoxy based material,and wherein a secondary material of the two materials comprises anelectrically conducting material. Thus, the dam may comprise these twomaterials separate from each other. The secondary material is differentfrom the primary material. The primary material, which is the epoxybased material, may comprise no electrically conducting material. Theprimary material comprising the epoxy based material may be in thecentre of the dam. The secondary material comprising the electricallyconducting material may be on the outside surface of the dam surroundingthe centre of the dam. It is an advantage to use two separate materialsfor the dam, as the electrically conducting material, such as silver,may be expensive to use, and if only the outside surface of the dam iswith this material, and the centre of the dam is an inexpensivematerial, then the cost may be reduced.

In some embodiments, the two materials of the dam are applied to thesubstrate in one step by using a nozzle having at least two outlets. Thedam material may be applied to the substrate through a nozzle. Thenozzle may have more outlets, as an epoxy based material may be atwo-component material, which may first be mixed when applied to thesubstrate, thus a nozzle applying an epoxy based material may have twooutlets for the epoxy based material itself. Thus, the electricallyconducting material, such as the silver material may be applied througha third outlet of nozzle. The electrically conducting material may alsocomprise an epoxy based material, thus even more outlets of the nozzlemay be used.

In some embodiments, the dam material defines a dam surrounding an areaof the substrate. The area may comprise the electronic components to beencapsulated.

In some embodiments, the substrate comprises a conductive trackinterconnected with a ground plane of the substrate. In some embodimentsthe dam material is provided on at least a part of the conductive track.The conductive track may be interconnected with the ground plane througha “via” or via a “through hole” in the substrate. The dam material maybe provided on top of the ground ring. The conducting material of thedam may be placed on top of a trace connected to the ground connectionof the substrate. It is an advantage that hereby electrical grounding isobtained.

In some embodiments, the dam material is cured before the fillencapsulation material is provided. In some embodiments, the dammaterial and the fill encapsulation material are cured together. In someembodiments, the cover material, the fill encapsulation material and dammaterial are cured together. In some embodiments, the environmentalprotection, the cover material, the fill encapsulation material and dammaterial are cured together. The curing may be thermal curing, and/or UVcuring, and/or curing over time. The dam material may have a high fillerloading. The fill material may have low filler loading.

It is an advantage of UV-curing that it allows rapid setting of thematerials in just a few seconds by applying UV light onto the material.This makes the material suitable for encapsulating components in fullyautomated high-volume production.

It is an advantage to use thermal curing at it allows for curing also indark areas that the UV light cannot reach. Thus, if the material, suchas the fill encapsulation material, is in black colour, the material canbe cured using thermal curing.

In some embodiments, the one or more electronic components are surfacemounted components (SMC), surface mounted devices (SMD) or discretecomponents. In some embodiments, the one or more electronic componentsare integrated circuit chips. In some embodiments, the one or moreelectronic components comprises a system-in-a-package. In someembodiments, the one or more electronic components is a plurality ofelectronic components. In some embodiments, at least one of the one ormore electronic components is a surface mounted component or a discretecomponent. In some embodiments, at least one of the one or moreelectronic components is an integrated circuit chip. In someembodiments, at least one of the one or more electronic components is asystem-in-a package. The surface mounted components or discretecomponents may be transistors, resistors, transducers, capacitors,integrated circuits, inductors, diodes, signal processing units,batteries etc. The integrated circuit chips may be silicon chips. Thesystem-in-a-package may be a hybrid.

The one or more electronic components may comprise a power supply unitsuch as switch-mode power supply e.g. comprising a switch capacitor oran inductor, e.g. as the first electronic component. The one or moreelectronic components may comprise a receiver such as a speaker, amicrophone, a filter, an antenna e.g. a magnetic radio, and/or aninterface.

The one or more electronic components may generate electromagneticfields of different magnitudes and at different frequencies, therebycreating electromagnetic interference between the electronic components,the electromagnetic interference being more or less disturbing for otherelectronic components e.g. depending on the operating frequencies of theelectronic components and the magnitude of the electromagnetic fields.

The one or more electronic components may comprise a first electroniccomponent and optionally a second electronic component on the substrate.The one or more electronic components, such as the first electroniccomponent and/or the second electronic component may be mounted to e.g.by being soldered, embedded in the substrate, or bonded e.g. wire bondedor adhesive bonded to the substrate. The method may comprise mounting aplurality of electronic components on the substrate.

Surface mounted devices or components may be assembled using asurface-mount technology (SMT) which is a method for producingelectronic circuits in which the components are mounted or placeddirectly onto the surface of printed circuit boards (PCBs). Anelectronic device so made is called a surface-mount device (SMD). Inindustry, it has largely replaced the through-hole technologyconstruction method of fitting components with wire leads into holes inthe circuit board. Both technologies can be used on the same board, withthe through-hole technology used for components not suitable for surfacemounting such as large transformers and heat-sinked powersemiconductors. By employing SMT, the production process speeds up. AnSMT component is usually smaller than its through-hole counterpartbecause it has either smaller leads or no leads at all. It may haveshort pins or leads of various styles, flat contacts, a matrix of solderballs (BGAs), or terminations on the body of the component.

In some embodiments, the substrate is a printed circuit board (PCB), ora carrier printed circuit board (PCB), or a panel configured to bemounted on a printed circuit board. In some embodiments, asystem-in-a-package is produced on a PCB panel and then singulated for“pick and place” SMD (surface mounted device) process. The substrate maybe configured to mechanically support and electrically connect one ormore electronic components using e.g. conductive tracks or pads. Thesubstrate may comprise one or more sheet layers of a conductive layer,laminate, or film such as of copper e.g. laminated onto and/or betweensheet layers of a non-conductive substrate.

In some embodiments, encapsulation of the one or more electroniccomponents comprises encapsulation of at least some of the electroniccomponent surfaces which are exposed to the surroundings. The surface ofthe electronic components (EC) may point “downwards” towards thesubstrate, point to the “sides” towards the inside walls of the dam orpoint “upwards” towards the cover material. In particular, the surfacesof the EC pointing towards the sides of the dam and upwards towardssurrounding may be encapsulated. However, the electronic components (EC)may not “stand” or “touch” on the substrate with their entire bottomsurface, the EC may “float” a few micrometers or millimeters above thesubstrate with the majority of the their bottom surface and just beconnected to be substrate at a few smaller connection points.

According to an aspect, disclosed is a system comprising one or moreelectronic components on a substrate. The one or more electroniccomponents are encapsulated on the substrate. The encapsulation of theone or more electronic components comprises a dam on the substrate. Thedam is provided around the one or more electronic components. The damcomprises a dam material comprising an electrically conducting material.The encapsulation of the one or more electronic components comprises afill encapsulation material within the dam on the substrate. The fillencapsulation material encapsulates the one or more electroniccomponents. The fill encapsulating material comprises a first surface.The encapsulation of the one or more electronic components comprises acover material on the first surface of the fill encapsulation material.The cover material comprising an electrically conducting material.Whereby the one or more electronic components are encapsulated andelectromagnetically shielded.

In some embodiments, the one or more electronic components areencapsulated according to the method disclosed above.

According to an aspect, disclosed is hearing device comprising one ormore electronic components on a substrate. The one or more electroniccomponents are encapsulated on the substrate. The encapsulation of theone or more electronic components comprises a dam on the substrate. Thedam is provided around the one or more electronic components. The damcomprises a dam material comprising an electrically conducting material.The encapsulation of the one or more electronic components comprises afill encapsulation material within the dam on the substrate. The fillencapsulation material encapsulates the one or more electroniccomponents. The fill encapsulating material comprises a first surface.The encapsulation of the one or more electronic components comprises acover material on the first surface of the fill encapsulation material.The cover material comprising an electrically conducting material.Whereby the one or more electronic components are encapsulated andelectromagnetically shielded.

In some embodiments, the one or more electronic components areencapsulated according to the method disclosed above.

The present disclosure relates to different aspects including the methoddescribed above and in the following, and corresponding methods, hearingdevices, systems, system parts, devices, networks, kits, uses and/orproduct means, each yielding one or more of the benefits and advantagesdescribed in connection with the first mentioned aspect, and each havingone or more embodiments corresponding to the embodiments described inconnection with the first mentioned aspect and/or disclosed in theappended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other features and advantages will become readily apparentto those skilled in the art by the following detailed description ofexemplary embodiments thereof with reference to the attached drawings,in which:

FIGS. 1a ) and 1 b) schematically illustrates an example of method 100for encapsulating one or more electronic components on a substrate.

FIGS. 2a ), 2 b), 2 c) and 2 d) schematically illustrate an example of asubstrate 4 with encapsulated electronic components 2 and a method orprocess for encapsulating the one or more electronic components 2 on thesubstrate 4.

FIGS. 3a ), 3 b), 3 c), 3 d) and 3 e) schematically illustrate anexample of a substrate 4 with encapsulated electronic components 2 and amethod or process for encapsulating the one or more electroniccomponents 2 on the substrate 4.

FIG. 4 schematically illustrates an example of a hearing device 20.

FIGS. 5a ) and 5 b) schematically illustrate an example of ablock-diagram of an embodiment of a hearing device 200.

DETAILED DESCRIPTION

Various embodiments are described hereinafter with reference to thefigures. Like reference numerals refer to like elements throughout. Likeelements will, thus, not be described in detail with respect to thedescription of each figure. It should also be noted that the figures areonly intended to facilitate the description of the embodiments. They arenot intended as an exhaustive description of the claimed invention or asa limitation on the scope of the claimed invention. In addition, anillustrated embodiment needs not have all the aspects or advantagesshown. An aspect or an advantage described in conjunction with aparticular embodiment is not necessarily limited to that embodiment andcan be practiced in any other embodiments even if not so illustrated, orif not so explicitly described.

Throughout, the same reference numerals are used for identical orcorresponding parts.

FIGS. 1a ) and 1 b) schematically illustrates an example of method 100for encapsulating one or more electronic components on a substrate.

In FIG. 1a ), the method 100 comprises providing 102 a dam on thesubstrate. The dam is provided around the one or more electroniccomponents. The dam comprises a dam material comprising an electricallyconducting material. The method 100 comprises providing 106 a liquidfill encapsulation material within the dam on the substrate. The fillencapsulation material encapsulates the one or more electroniccomponents. The fill encapsulation material is configured to solidify.The solidified fill encapsulating material comprises a first surfaceexposed to surroundings. The method 100 comprises applying 110 a covermaterial on the first surface of the solidified fill encapsulationmaterial. The cover material comprises an electrically conductingmaterial. Thereby the one or more electronic components are encapsulatedand electromagnetically shielded.

In FIG. 1b ), the method 100 comprises providing 102 a dam on thesubstrate. The dam is provided around the one or more electroniccomponents. The dam comprises a dam material comprising an electricallyconducting material. The method 100 comprises curing 104 the dammaterial. The method 100 comprises providing 106 a liquid fillencapsulation material within the dam on the substrate. The fillencapsulation material encapsulates the one or more electroniccomponents. The fill encapsulation material is configured to solidify.The solidified fill encapsulating material comprises a first surfaceexposed to surroundings. The method 100 comprises curing 108 the fillencapsulation material. The method 100 comprises applying 110 a covermaterial on the first surface of the solidified fill encapsulationmaterial. The cover material comprises an electrically conductingmaterial. The method 100 comprises performing a final curing 112 of thematerials. Thereby the one or more electronic components areencapsulated and electromagnetically shielded. The method 100 mayfurther comprise applying an environmental protection on the covermaterial and the outside walls of the dam.

FIG. 2 schematically illustrates an example of a substrate 4 withencapsulated electronic components 2 and a method or process forencapsulating the one or more electronic components 2 on the substrate4. The substrate 4 is seen from above, in a top view, in FIG. 2.

In FIG. 2a ), a substrate 4 is shown. The substrate 4 comprises one ormore electronic components 2. The substrate 4 may be a printed circuitboard. The electronic components 2 may be assembled on the substrate 4as surface mounted components. The electronic components may betransistors, capacitors, signal processing units etc. The electroniccomponents may be different components or the same components. Theelectronic components may have different sizes and shapes, such asdifferent height, different volumes etc.

In FIG. 2b ), a dam 6 is provided around the one or more electroniccomponents 2. The dam 2 comprises a dam material comprising anelectrically conducting material. The dam 6 is provided around some ofthe electronic components 2 on the substrate 4, and some of theelectronic components 2′ are not surrounded by the dam 6. The dam 2 maybe arranged at least partly on or in connection with a ground ring ofthe substrate 4.

In FIG. 2c ), a liquid fill encapsulation material 8 is provided withinthe dam 6 on the substrate 4. The fill encapsulation material 8encapsulates the one or more electronic components 2. The fillencapsulation material 8 is configured to solidify. The solidified fillencapsulating material 8 comprises a first surface exposed tosurroundings. The fill encapsulation material 8 may be dark, such asblack, as shown in this figure, or it may have another color.

In FIG. 2d ), a cover material 14 is applied on the first surface of thesolidified fill encapsulation material 8. The cover material 14comprises an electrically conducting material. Due to the electricallyconducting dam material and cover material, the one or more electroniccomponents 2 are encapsulated and electromagnetically shielded.

FIG. 3 schematically illustrates an example of a substrate 4 withencapsulated electronic components 2 and a method or process forencapsulating the one or more electronic components 2 on the substrate4. The substrate 4 is seen from the side in a cross-section, in a sidecross-section view, in FIG. 3.

In FIG. 3a ), a substrate 4 is shown. The substrate 4 comprises one ormore electronic components 2. The substrate 4 may be a printed circuitboard. The electronic components 2 may be assembled on the substrate 4as surface mounted components. The electronic components may betransistors, capacitors, signal processing units etc. The electroniccomponents may be different components or the same components. Theelectronic components may have different sizes and shapes, such asdifferent height, different volumes etc.

A ground ring 16 or a connection to a ground plane 16 is provided in thesubstrate 4.

In FIG. 3b ), a dam 6 is provided around the one or more electroniccomponents 2. The dam 2 comprises a dam material comprising anelectrically conducting material. The dam 6 is provided around some ofthe electronic components 2 on the substrate 4, and some of theelectronic components 2′ are not surrounded by the dam 6. The dam 6 maybe provided on the ground ring 16 or interconnected with a ground plane16. The height H of the dam 6 may be smaller than the height of thehighest of the electronic components. The height H of the dam 6 may beequal to the height of the highest of the electronic components. Theheight H of the dam 6 may be higher than the height of the highest ofthe electronic components. The width W of the dam 6 may be smaller thanthe height of the dam 6. The width W of the dam 6 may be equal to theheight of the dam 6. The width W of the dam 6 may be larger than theheight of the dam 6.

In FIG. 3c ), a liquid fill encapsulation material 8 is provided withinthe dam 6 on the substrate 4. The fill encapsulation material 8encapsulates the one or more electronic components 2. The fillencapsulation material 8 is configured to solidify. The solidified fillencapsulating material 8 comprises a first surface 10 exposed tosurroundings 12. The first surface 10 may point upwards in amanufacturing process. The first surface 10 may be parallel to thesubstrate 4. A vector normal to the first surface 10 may be parallel tothe substrate 4. The first surface 10 may be flat and homogenous.

In FIG. 3d ), a cover material 14 is applied on the first surface 10 ofthe solidified fill encapsulation material 8. The cover material 14comprises an electrically conducting material. Due to the electricallyconducting dam material 6 and cover material 14, the one or moreelectronic components 2 are encapsulated and electromagneticallyshielded.

In FIG. 3e ), an environmental protection 18 is applied on the covermaterial 14 and the outside walls of the dam 6.

FIG. 4 schematically illustrates an example of a hearing device 20, suchas a hearing aid. The hearing device 20 comprises a microphone 22, forreceiving an input signal and converting it into an audio signal. Theaudio signal is provided to a processing unit 24 for processing theaudio signal and providing a processed output signal for compensating ahearing loss of a user of the hearing device 20. A receiver 26 isconnected to an output of the processing unit 24 for converting theprocessed output signal into an output sound signal, e.g. a signalmodified to compensate for a user's hearing impairment. Typically, thereceiver 26 comprises a transducer, and the receiver 26 is oftenreferred to as a speaker. The processing unit 24 may comprise elementssuch as amplifiers, compressors, noise reduction systems, etc. Thehearing device 20 may further comprise a wireless communication unit 28for wireless data communication interconnected with an antenna structure30 for emission and reception of an electromagnetic field. The wirelesscommunication unit 28, such as a radio or a transceiver, connects to theprocessing unit 24 and the antenna structure 30, for communicating withan electronic device, an external device, or with another hearingdevice, such as another hearing aid located in/on/at another ear of theuser, typically in a binaural hearing system. The hearing device 20 maycomprise two or more antenna structures.

The hearing device 20 may be a behind-the-ear hearing device, and may beprovided as a behind-the-ear module. The hearing device 20 may be anin-the-ear hearing device and may be provided as an in-the-ear module.Alternatively, parts of the hearing device 20 may be provided in abehind-the-ear module, while other parts, such as the receiver 26, maybe provided in an in-the-ear module.

FIGS. 5a ) and 5 b) schematically illustrate an example of ablock-diagram of an embodiment of a hearing device 200. In FIG. 5a ),the hearing device 200 comprises a first transducer, i.e. microphone202, to generate one or more microphone output signals based on areceived an audio signal. The one or more microphone output signals areprovided to a signal processor 204 for processing the one or moremicrophone output signals. A receiver or speaker 206 is connected to anoutput of the signal processor 204 for converting the output of thesignal processor into a signal modified to compensate for a user'shearing impairment, and provides the modified signal to the speaker 206.

The hearing device signal processor 204 may comprise elements such as anamplifier, a compressor and/or a noise reduction system etc. The signalprocessor 204 may be implemented in a signal processing chip 204′. Thehearing device may further have a filter function, such as compensationfilter for optimizing the output signal.

The hearing device further comprises a wireless communication unit 214interconnected with magnetic induction antenna 216 such as a magneticinduction coil. The wireless communication unit 214 and the magneticinduction antenna 216 may be configured for wireless data communicationusing emission and reception of magnetic field. The wirelesscommunication unit may be implemented as a wireless communication chip214′, such as a magnetic induction control chip 214′. The hearing device200 further comprises a power source 212, such as a battery or arechargeable battery. Furthermore, a power management unit 210 isprovided for controlling the power provided from the battery 212 to thesignal processor 204, the receiver, the one or more microphones, thewireless communication unit (RF) 208, and the wireless communicationunit (Ml) 214. The magnetic induction antenna is configured forcommunication with another electronic device, in some embodimentsconfigured for communication with another hearing device, such asanother hearing device located at another ear, typically in a binauralhearing device system.

The hearing device may furthermore have a wireless communication unit208, such as a wireless communication circuit, for wireless datacommunication interconnected with an RF antenna 218 for emission andreception of an electromagnetic field. The wireless communication unitmay be implemented as a wireless communication chip 208′. The wirelesscommunication unit 208, including a radio or a transceiver, connect tothe hearing device signal processor 204 and the RF antenna 218, forcommunicating with one or more external devices, such as one or moreexternal electronic devices, including at least one smart phone, atleast one tablet, at least one hearing accessory device, including atleast one spouse microphone, remote control, audio testing device, etc.,or, in some embodiments, with another hearing device, such as anotherhearing device located at another ear, typically in a binaural hearingdevice system.

The signal processor 204, the wireless communication unit (RF) 208, thewireless communication unit (MI) 214 and the power management unit 210may be implemented as signal processing chip 204′, wirelesscommunication chip (RF) 208′, wireless communication chip (MI) 214′ andpower management chip 210′, respectively.

In FIG. 5b ), a hearing device corresponding to the hearing device asshown in FIG. 5a is seen, except that in FIG. 5b , only one wirelesscommunication unit 214 is present being interconnected with the magneticinduction antenna 216, the signal processor 204 and the power managementunit 210.

Likewise, even though not shown, also a hearing device having only onewireless communication unit 208 being interconnected with an RF antennafor reception and emission of an electromagnetic field is envisaged.

Although particular features have been shown and described, it will beunderstood that they are not intended to limit the claimed invention,and it will be made obvious to those skilled in the art that variouschanges and modifications may be made without departing from the scopeof the claimed invention. The specification and drawings are,accordingly to be regarded in an illustrative rather than restrictivesense. The claimed invention is intended to cover all alternatives,modifications and equivalents.

LIST OF REFERENCES

-   2 electronic components-   4 substrate-   6 dam-   8 fill encapsulation material-   10 first surface of solidified fill encapsulation material-   12 surroundings-   14 cover material-   16 ground ring or ground plane-   18 environmental protection-   20 hearing device-   22 microphone-   24 processing unit-   26 receiver-   28 wireless communication unit-   30 antenna structure-   200 hearing device-   202 first transducer, e.g. microphone-   204 signal processor-   204′ signal processing chip-   206 receiver or speaker-   208 wireless communication unit (RF)-   210 power management unit-   212 power source-   214 wireless communication unit (MI)-   214′ wireless communication chip-   216 magnetic induction antenna-   218 RF antenna-   100 method-   102 providing a dam on a substrate-   104 curing dam-   106 providing a liquid fill encapsulation material within the dam on    the substrate-   108 curing fill encapsulation material (and dam)-   110 applying a cover material on the first surface of the solidified    fill encapsulation material-   112 final curing

1. A method for covering one or more electronic components on asubstrate, the method comprising: providing a dam on the substrate,wherein the dam is provided around the one or more electroniccomponents, the dam comprising a dam material, wherein the dam materialcomprises an electrically conductive material; providing a liquidencapsulation material within the dam, wherein the liquid encapsulationmaterial is provided to encapsulate the one or more electroniccomponents, the liquid encapsulation material configured to solidify toform a solidified encapsulating material having a first surface; andapplying a cover material over the first surface of the solidified fillencapsulation material, wherein the one or more electronic componentsare at least partly electromagnetically shielded by the cover material.2. The method of claim 1, wherein the cover material is provided on thefirst surface of the solidified fill encapsulation material.
 3. Themethod of claim 1, wherein the cover material, and/or the solidifiedencapsulation material and/or the dam material are configured to connectto each other.
 4. The method of claim 1, wherein the dam material,and/or the liquid encapsulation material, and/or the cover materialcomprise(s) an epoxy-based material, an acrylic based material and/or apolymer-based material.
 5. The method of claim 1, wherein the dammaterial comprises a first material, which is a mixture of anepoxy-based material and the electrically conductive material.
 6. Themethod of claim 1, wherein the dam material comprises at least a primarymaterial and a secondary material, wherein the primary materialcomprises an epoxy-based material, and wherein the secondary materialcomprises the electrically conductive material.
 7. The method of claim1, wherein the substrate comprises a conductive track interconnectedwith a ground plane of the substrate, and wherein the dam is on at leasta part of the conductive track.
 8. The method of claim 1, wherein thedam material is cured before the liquid encapsulation material isprovided.
 9. The method of claim 1, wherein the dam material and theliquid encapsulation material are cured together.
 10. The method ofclaim 1, wherein the one or more electronic components comprise surfacemounted component(s) or discrete component(s).
 11. The method of claim1, wherein the one or more electronic components comprise integratedcircuit chip(s).
 12. The method of claim 1, wherein the one or moreelectronic components comprise a system-in-a-package.
 13. The method ofclaim 1, wherein the substrate is a printed circuit board (PCB).
 14. Themethod of claim 1, wherein the substrate is a carrier printed circuitboard (PCB).
 15. The method of claim 1, wherein the substrate is a panelconfigured to be mounted on a printed circuit board.
 16. The method ofclaim 1, wherein the one or more electronic components are a subset ofcomponents on the substrate.
 17. The method of claim 1, wherein at leastsome of the liquid encapsulation material is provided on the substrate.18. The method of claim 1, wherein the one or more electronic componentsare at least partly electromagnetically shielded by the dam.
 19. Themethod of claim 1, wherein the first surface of the solidifiedencapsulating material is exposed to a surrounding before the covermaterial is applied.
 20. The method of claim 1, wherein the covermaterial is electrically conductive.
 21. A system comprising: asubstrate; one or more electronic components on the substrate; a dam onthe substrate, the dam surrounding the one or more electroniccomponents, the dam comprising a dam material, wherein the dam materialcomprises an electrically conductive material; an encapsulation materialwithin the dam, the encapsulation material encapsulating the one or moreelectronic components, the encapsulating material comprising a firstsurface; a cover material disposed over the first surface of theencapsulation material, the cover material configured to at least partlyelectromagnetically shield the one or more electronic components. 22.The system of claim 21, wherein the system is a hearing device.
 23. Thesystem of claim 21, wherein the dam material comprises a mixture of anepoxy-based material and the electrically conductive material.
 24. Thesystem of claim 21, wherein the substrate comprises a conductive trackinterconnected with a ground plane of the substrate, and wherein the damis on at least a part of the conductive track.
 25. The system of claim21, wherein the one or more electronic components comprise surfacemounted component(s) or discrete component(s).
 26. The system of claim21, wherein the one or more electronic components comprise integratedcircuit chip(s).
 27. The system of claim 21, wherein the one or moreelectronic components comprise a system-in-a-package.
 28. The system ofclaim 21, wherein the substrate is a printed circuit board (PCB). 29.The system of claim 21, wherein the substrate is a carrier printedcircuit board (PCB).
 30. The system of claim 21, wherein the substrateis a panel configured to be mounted on a printed circuit board.
 31. Thesystem of claim 21, wherein at least some of the encapsulation materialis on the substrate.
 32. The system of claim 21, wherein the one or moreelectronic components are at least partly electromagnetically shieldedby the dam.